Discovery of a Deep-Sea Ecosystem Living Without Sunlight in the Galapagos Rift

In 1977, the research submarine Alvin dove to a depth of approximately 2,500 meters in the Galapagos Rift. During this dive, conducted by geologists to examine the environment, massive white clam shells and clusters of worms were observed around volcanic fissures. This finding meant the discovery of the first known large ecosystem relying on chemical energy from the Earth's interior instead of sunlight.

The discovery was actually recorded not by a single momentary glimpse, but through a step-by-step process. Photos taken before the dive had indicated an unusual habitat on the seafloor and guided researchers to the area. The smell of hydrogen sulfide in water samples taken from the region proved that, instead of plant photosynthesis, bacteria were performing chemosynthesis to provide energy for these creatures.

The giant tube worms found in the region, known as Riftia pachyptila, are among the most striking examples of this chemical-based life. These worms lack a mouth and digestive system; instead, they harbor billions of bacteria inside them. These creatures, which feed on the organic matter produced by the bacteria, reveal how life on our planet can evolve under different conditions.